Smoke Detectors: Part III

Mike

Senior Member
Ok, the threads so far have been great. Last question (I think):

I need to put something in the kitchen, so I was looking at thermal sensors / fixed / rate of rise detectors.

I currently have System Sensor 2 wire smoke detectors

1: Any recommendations on these type of detectors (fixed, rate of rise, etc)?
2: Does the same recommendation/requirement apply of using the same manufacturer as the other smokes? (which would make sense since they will all be wired on the same zone, right?)
 
A rate-of-rise sensor is just a thermal switch so brand should not be important. Usual considerations are fixed temp limit (135 interior and something higher for attics etc.) and resettable vs. not.
 
My building inspector recommended (it wasn't required) a combination smoke-CO detector for the kitchen, if you cook with gas. However, he stated that a smoke-detector is best on the ceiling, while a CO-detector is best half-way up the wall (I don't know why).
 
Hmm, I had a reply all set, but I later determined it was not correct (and deleted it).

It had to do with atomic weight of carbon (12) and oxygen (16). CO would have a weight of 28 and oxygen would have a weight of 32. Later determined I didn't know what I was talking about. :)
 
rocco said:
My building inspector recommended (it wasn't required) a combination smoke-CO detector for the kitchen, if you cook with gas. However, he stated that a smoke-detector is best on the ceiling, while a CO-detector is best half-way up the wall (I don't know why).
That brings up two interesting points:

1. I forgot about the CO detector. I don't cook with gas and have electric stoves and oil heat (so I don't think I need one though anywhere in the house). The only gas I have is propane for the grill, don't think that warrants a co2 detector in the garage where the spare tank goes.

2. I thought it was recommended to avoid smokes in the kitchen because they could false alarm. If I can just add another of what I bought I'm covered by the earlier decision to use System Sensor 2 wire smoke detectors. Maybe you just put another panel near or in the kitchen to cover the situations where it is a false alarm if it happens?
 
And that brings up two other interesting points:
don't think that warrants a co2 detector in the garage where the spare tank goes.
and I recently learned that a CO detector will not detect propane, unless the propane is burning.
I thought it was recommended to avoid smokes in the kitchen because they could false alarm.
Yes. we discussed that, and he said that was why smoke-detectors were not required for kitchens. He recommended, however, to put up with the false alarms, since a large percentage of fires start in the kitchen.
 
1: Any recommendations on these type of detectors (fixed, rate of rise, etc)?

I'm not sure you can even get heat detectors without rate of rise anymore, but get units with both.

2: Does the same recommendation/requirement apply of using the same manufacturer as the other smokes? (which would make sense since they will all be wired on the same zone, right?)

As upstatemike mentions, heats are very simple (all mechanical, no electronics) and brand doesn't matter. However, IIRC you shouldn't put heats and smokes on the same circuit, as heats are not "life safety"devices as defined in the code. If my intelligence gets back up into the triple digits later today (just got off a 24 hour duty shift, the brain MIGHT be firing on 2 out of 12 cylinders if I'm lucky), I'll dig up some paperwork to check.

My building inspector recommended (it wasn't required) a combination smoke-CO detector for the kitchen, if you cook with gas. However, he stated that a smoke-detector is best on the ceiling, while a CO-detector is best half-way up the wall (I don't know why).

The inspector is right about the mounting locations, but wrong about the smoke detector in the kitchen. In fact, I'm pretty sure the code specifically recommends to AVOID putting one in the kitchen, along with high humidity locations such as bathrooms. CO detectors should be mounted around chest level (actually it's "mouth" level, but who's mouth do you use? Shaq's? Mini-me's?), while smokes go on the ceiling or high on the wall. There are also some limitation with smokes about corners, ceiling ridges, and the top 6 inches on walls (don't for all of them).

I recently learned that a CO detector will not detect propane, unless the propane is burning.

Correct. CO is created during combustion (and political speeches), so putting a CO detector near gas storage is a waste. CO detectors should be at chest height, preferably near the sleeping areas. You can get LP gas detectors, but I wouldn't bother for garage storage of spare bottles. I have LP detectors near the propane furnace, gas cooktop, and gas fireplace. You can also get a natural gas version. IIRC (see brain comments above), the natural gas versions are mounted near the ceiling, while LP is mounted near the floor.
 
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